Number of rooted graceful labelings with n edges.

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =24a(5) =108a(6) =596a(7) =3674a(8) =26068a(9) =202470a(10) =1753884a(11) =16435754a(12) =168174596a(13) =1842418704a(14) =21757407158a(15) =272771715272